*font{
    font-weight: bolder; /* 加粗 */
    font-size: 28px;
    margin: 0px;
}
#container{
    margin: 0 auto;
    width: 900px;
}
#header{
    height: 100px;
    background-color: #6cf;
    margin-bottom: 5px;
}

#maincontent{
    margin-bottom: 5px;
}
#sidebar{
    width: 200px;
    height: 500px;
    float: left;
    background-color: #9ff;
}
#content{
    width: 695px;
    height: 500px;
    float: right;
    background-color: #cff;
}